With the advent of large scale distributed computer systems such as the Internet, the amount of information which has become available to users of computer systems has exploded. Among this information is electronic mail (e-mail). With the improvements in means for composing and distributing written messages, the amount of e-mail traffic on the Internet has surged. It is not unusual for an active Internet user to be exposed to tens of thousands of e-mail messages a year.
As an advantage, the Internet allows users to interchange useful information in a timely and convenient manner. However, keeping track of this huge amount of information has become a problem. As an additional advantage, the Internet now allows users to exchange information in a number of different presentation modalities, such as text, audio, and still and moving images. Adapting e-mail systems to organize such complex information, and providing efficient means to coherently retrieve the information is not trivial.
As a disadvantage, Internet users may receive junk-mail whenever they send to mailing lists or engage in news groups. There are numerous reported incidents where specific users have been overwhelmed by thousands of unwanted mail messages. Current filtering systems are inadequate to deal with this deluge.
Known distributed systems for composing and accessing e-mail are typically built around protocols such as Internet Messaging Access Protocol (IMAP), Post Office Protocol (POP), or Simple Mail Transfer Protocol (SMTP). Typically, users must install compatible user agent software on any client computers where the mail service is going to be accessed. Often, a significant amount of state information is maintained in the users' client computers. For example, it is not unusual to store the entire mail database for a particular user in his desk-top or lap-top computer. Normally, the users explicitly organize mail messages into subject folders. Accessing mail generally involves shipping entire messages over the network to the client computer.
Such systems are deficient in a number of ways. Most computers that a user will encounter will not be configured with user agents compatible with the user's mail service. Often, a user's state is captured in a specific client computer which means that work cannot proceed when the user moves to another computer. Managing large quantities of archival mail messages by an explicit folder organization is difficult for most users. Accessing mail over a low bandwidth network tends to unsatisfactory.
Therefore, it is desired to provide a mail system that overcomes these deficiencies.